The hair pull test is one of the simplest and most useful bedside diagnostic procedures in dermatology. The technique involves gently grasping 50–60 hairs between thumb and forefinger and applying steady traction along the hair shaft. The number of hairs that come out provides quantitative information about the rate of telogen shedding. The procedure should be performed on hair that hasn't been washed for 24+ hours to capture accumulated telogen hairs.
Normal results: fewer than 3 hairs extracted from a pull of 50–60. More than 6 hairs extracted suggests active telogen effluvium. Microscopic examination of extracted hairs adds diagnostic value, telogen hairs have a distinctive club-shaped root, anagen hairs have an attached pigmented root sheath, and dystrophic hairs (broken shaft, abnormal root) suggest specific pathologies. The technique is reproducible with standardised pressure and consistent technique.
Practical value: positive hair pull tests confirm active shedding and warrant workup for telogen effluvium causes (thyroid, iron, recent stressors, medications). Negative results in patients reporting hair loss suggest either resolved telogen effluvium, slow androgenetic alopecia progression, or perception-only issues. The procedure can be self-administered at home, though interpretation benefits from clinical context. Patients tracking treatment response can use serial hair pull tests as a simple objective measure of shedding rate over time.
Discussion (3)
AnonymousDad
9 months ago
This matches my own experience. Two years in and the picture is more nuanced than the early hype suggested.
Sophie L.
9 months ago
Really useful breakdown. The mechanism part was the bit I'd been struggling to understand.
Daniel R.
9 months ago
The cost/benefit case here is much weaker than the marketing implies. Useful that someone said it clearly.
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